Major goal is to begin a new and exciting project on sex steroid production in elderly men with prostate hyperplasia. Preliminary work in our lab. suggests that dihydrotestosterone blood levels in men with prostate disease are elevated. We will study men with prostate disease and ascertain whether blood levels of androgen (which are related to prostate growth) may be a marker for prostate hyperplasia patients and whether changes after prostate surgery will reflect surgical success. This project will involve use of radioassays of testosterone, dihydrotestosterone, and 3 alpha-androstanediol as well as studies of blood production rates and inter-conversion of testosterone to dihydrotestosterone in normals and patients with prostate hyperplasia.